The present invention relates to a method for screening of polycondensation catalysts, wherein at least two polycondensation catalysis reactions are performed simultaneously under substantially equivalent conditions in at least two reaction cells, using a sample comprising material to be polycondensated and a catalyst to be screened, and wherein the performances of the catalysts are analyzed.
Polycondensation catalysts vary in their ability to speed up the reactions for polymerizing e.g. polyesters, particularly for those prepared from diols and diacids (or diesters). Polycondensation reactions and catalysts are known in the field. Examples of polycondensation catalysts are e.g. Ti(OBu)4, Ti(O-iPr)4, Sb(OBu)3, Al(O-sBu)3, Ge(OEt)4, etc.
In practice polycondensation catalyst are screened using classical laboratory equipment, e.g. glass or metal reaction vessel, stirrer, etc.
A problem of the known methods for screening polycondensation catalysts is that laboratory screening takes about a day per polymerization. Furthermore polycondensation catalysis reactions have to be carried out on a scale of at least 10 g to 1000 g, commonly about 100 g to 500 g. Also, results obtained using conventional screening methods are not predictable for catalyst activities on a large, i.e. industrial scale.
The above problems are particularly pertinent when a large amount of catalysts have to be screened, especially when only a small amount of starting material, e.g. less than 10 g, is available.
It is an object of the present invention to avoid the above problems and to provide a more efficient method for screening polycondensation catalysts.
It is a further object of the present invention to provide a new method for screening of polycondensation catalysts, that can also be used for small amounts of sample.